Executive Summary of 602‎(a)‎ Storage Guideline

• Description: Executive Summary of 602‎(a)‎ Storage Guideline
• State: CO
• Title: Executive Summary of 602‎(a)‎ Storage Guideline
• Water Supply Pro - Doc Type: Meeting

EXECUTIVE SUMMARY
The Secretary of the Interior, acting through the Bureau of Reclamation, is proposing the
adoption of a 602(a) storage guideline that will assist the Secretary of the Interior in making a
determination of the quantity of water considered necessary as of September 30 of each year, to
assist in implementation of and as required by Article II (1) of the 1970 Criteria for Coordinated
Long -Range Operation of Colorado River Reservoirs (Long -Range Operating Criteria) pursuant
to the Colorado River Basin Project Act of September 30, 1968. The proposed 602(a) storage
guideline would remain in effect through calendar year 2016.
In Section 602(a) of the Colorado River Basin Project Act, Congress instructed the Secretary of
the Interior (in consultation with representatives of the Colorado River Basin States) to make an
annual determination of the quantity of water considered necessary to be in storage in Upper
Basin reservoirs to provide protection to the Upper Division States of Colorado, ew IG exico,
Utah, and Wyoming against drought in the Colorado River Basin. This quantity of water is
commonly referred to as "602(a) storage." This determination is important because the 602(a)
storage requirement is the "trigger" point for making storage equalization releases from Lake
Powell to Lake Mead. In years when projected storage in Upper Basin reservoirs is greater than
602(a) storage, and Lake Powell storage is greater than storage at Lake Mead, storage
equalization releases are made. Such storage equalization releases are made to maintain, as
nearly as practicable, the active storage in Lake Mead equal to the active storage in Lake Powell
on September 30. In years when projected storage in the Upper Basin is less than 602(a) storage,
such storage equalization releases from Lake Powell are not made and the objective is to
maintain a release of a minimum of 8.23 million acre -feet as specified in the Long -Range
Operating Criteria.
In July 2000, the Bureau of Reclamation issued a draft environmental impact statement on the
proposed adoption of specific criteria, applicable for 15 years, under which surplus water
conditions would be determined, and accordingly surplus water made available, for use by the
Lower Division States of Arizona, California, and Nevada. During the public comment period
on the document, the seven Colorado River Basin States submitted information to the
Department of the Interior that contained a proposal for interim surplus criteria and a number of
other related issues. This information was published in the Federal Register on August 8, 2000
(65 FR 48531 -38). One component of the seven Colorado River Basin States' proposal is
Section V, "Determination of 602(a) Storage in Lake Powell During the Interim Period," and
reads as follows:
During the interim period, 602(a) storage requirements determined in accordance
with Article II (1) of the Criteria [Long -Range Operating Criteria] shall u` tilize a
value of not less than 14.85 million acre -feet (elevation 3,630 feet) for Lake
The Proposed Action Alternative analyzed herein would adopt the Basin States' recommendation
to limit 602(a) storage equalization releases whin the storage level in Lake Powell is projected to
be below 14.85 million acre -feet (elevation 3,630 feet) on September 30 as an added
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